syzkaller has found reproducer for the following crash on  
4131d5166185d0d75b5f1d4bf362a9e0bac05598
git://git.cmpxchg.org/linux-mmots.git/master
compiler: gcc (GCC) 7.1.1 20170620
.config is attached
Raw console output is attached.

syzkaller reproducer is attached. See https://goo.gl/kgGztJ
for information about syzkaller reproducers


BUG: unable to handle kernel NULL pointer dereference at 00000000c58b0b19
IP: sha512_mb_mgr_get_comp_job_avx2+0x6e/0xee  
arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S:251
PGD 1cb562067 P4D 1cb562067 PUD 1cb563067 PMD 0
Oops: 0002 [#1] SMP KASAN
Dumping ftrace buffer:
    (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 24 Comm: kworker/1:1 Not tainted 4.15.0-rc1-mm1+ #29
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: crypto mcryptd_queue_worker
task: 0000000018ff7174 task.stack: 000000004c6e7fb4
RIP: 0010:sha512_mb_mgr_get_comp_job_avx2+0x6e/0xee  
arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S:251
RSP: 0018:ffff8801d9d171b8 EFLAGS: 00010002
RAX: 0000000000000000 RBX: ffff8801d5aa38d0 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff8801d5aa3780
RBP: ffff8801d9d171e0 R08: 0000000100000000 R09: 0000000000000001
R10: 0000000000000002 R11: 0000000000000003 R12: ffff8801d5aa3780
R13: 0000000000000282 R14: ffff8801cc115760 R15: ffffe8ffffd10630
FS:  0000000000000000(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000060 CR3: 00000001cb55f000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  sha_complete_job+0x276/0x830 arch/x86/crypto/sha512-mb/sha512_mb.c:510
  sha512_mb_update+0x2f6/0x530 arch/x86/crypto/sha512-mb/sha512_mb.c:610
  crypto_ahash_update include/crypto/hash.h:522 [inline]
  ahash_mcryptd_update crypto/mcryptd.c:628 [inline]
  mcryptd_hash_update+0xcd/0x1c0 crypto/mcryptd.c:374
  mcryptd_queue_worker+0xfe/0x660 crypto/mcryptd.c:182
  process_one_work+0xbfd/0x1bc0 kernel/workqueue.c:2113
  worker_thread+0x223/0x1990 kernel/workqueue.c:2247
  kthread+0x37a/0x440 kernel/kthread.c:238
  ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:517
Code: 49 0f 42 d3 48 f7 c2 f0 ff ff ff 0f 85 9a 00 00 00 48 83 e2 0f 48 6b  
da 08 48 8d 9c 1f 48 01 00 00 48 8b 03 48 c7 03 00 00 00 00 <c7> 40 60 02  
00 00 00 48 8b 9f 40 01 00 00 48 c1 e3 08 48 09 d3
RIP: sha512_mb_mgr_get_comp_job_avx2+0x6e/0xee  
arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S:251 RSP:  
ffff8801d9d171b8
CR2: 0000000000000060
---[ end trace 2003a6fbb2bb168e ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
    (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..